[en] Numerous atmospheric dispersion models have been developed for use in the nuclear industry. Such models are used to determine relative concentrations of airborne radionuclides at various locations as a result of routine or accidental releases from nuclear facilities. These concentrations are required input to dose assessments for environmental and safety analyses. The West Valley Demonstration Project (WVDP) has developed and implemented a meteorological program to address the effects of complex hill and valley terrain upon dispersion of the project's atmospheric releases. Wind, temperature, and atmospheric stability data collected from seven different locations near the site over a complete annual cycle were used as input to a wind field model. The wind fields were constructed by using the data measured at the various locations and interpolating between the measurement sites on a two dimensional grid. Due to the availability of representative terrain-influenced wind measurements, the effects of local surface roughness, terrain channeling and sheltering, and surface heating and cooling were explicitly factored into the placement of wind vectors on the grid. Wind fields were developed to cover the range of meteorological conditions encountered, for every hour in the full year data set. The wind fields thus generated are coupled with a standard variable trajectory Gaussian puff model to develop site-specific relative concentrations (x/Q values) for input to the radiological dose module of the AIRDOS-EPA computer code which then calculates site-specific impacts from the atmospheric pathways for various radiological sources. 16 refs., 15 figs., 38 tabs